The microelectronic industry relies on a variety of wet/dry process recipes in the manufacture of a variety of microelectronic devices. The microelectronic industry can utilize a variety of configured systems to carry out such wet/dry processes. Many such systems are in the form of spray processor tools. A spray processor tool generally refers to a tool in which one or more treatment chemicals, rinsing liquids, and/or gases are sprayed onto one or more wafers either singly or in combination in a series of one or more steps. This is in contrast to wet bench tools where wafers are immersed in a fluid bath during the course of processing. In a typical spray processor tool, fluid is sprayed onto the wafer(s) while the wafer(s) are supported upon a rotating platen such as a turntable, chuck, or the like. Examples of spray processor systems include the MERCURY® or ZETA® spray processor systems available from FSI International, Inc., Chaska, Minn.; the SCEPTER™ or SPECTRUMS® spray processor systems available from Semitool, Inc., Kalispell, Mont.; a spray processor system available from SEZ AG, Villach, Austria and sold under the trade designation SEZ 323; and the like.
Typical recipes for spray processor tools may include process steps involving subjecting wafer(s) first to one or more wet processes (e.g., chemical treatments and/or rinsing treatments) after which the wafer(s) then are dried. For example, a conventional rinse/dry sequence may involve first spraying a rinsing liquid onto stacks of wafer(s) supported upon a rotating turntable in a process chamber. Rinsing is stopped and the plumbing used to deliver the rinse liquid is then purged into the process chamber. A drying gas may then be introduced into the chamber through the same or different plumbing to dry the wafer(s).
One way by which the effectiveness of a particular process recipe can be assessed is by measuring the degree to which particles are added to wafer(s) following a treatment in accordance with the process recipe. It is generally desirable that the number of added particles (i.e., added particles=measured particles after process recipe—measured particles before process recipe) is consistently as low as possible.
Some process recipes may perform well with respect to added particles only within a relatively narrow range of process parameters. For example, a conventional rinse/dry recipe may be practiced so as to yield consistently low added particles only when the rinse liquid is within a particular temperature range (e.g., moderately warm). Yet, this same recipe might suffer from unduly high and/or inconsistent added particles if the rinse liquid is at a temperature outside such range (e.g., if the rinse liquid is chilled or hot). This temperature restriction can limit the practical utility of such a recipe. For instance, it might otherwise be desirable to be able to use very hot rinse liquid to reduce cycle time, inasmuch as the hotter liquid might rinse wafer(s) faster and dry faster. Further, it might otherwise be desirable to be able to use very cold rinse liquid to treat temperature sensitive substrates. In short, conventional rinse/dry sequences may tend to be unduly temperature sensitive with respect to added particles, often at the expense of process flexibility.
As microelectronic device features become smaller and smaller, the size restrictions upon added particles become more stringent. For example, for larger-sized features, monitoring added particles that are greater than 150 nm in size (Such a specification is often referred to as “particles >150 nm” or another similar reference.) might be sufficient to help ensure acceptable device quality. However, for smaller features, monitoring particles >90 nm, or >65 nm, or even smaller added particles may be desirable. Some conventional rinse/dry sequences may perform well with less stringent monitoring, but may not perform as well as might be desired when monitoring smaller added particles.
There is a continuing need, therefore, in the microelectronics industry to carry out wet/dry process recipes with consistently lower added particles. In particular, there is a continuing need in this area to provide approaches that are more temperature insensitive and/or that provide lower added particles even when more stringent monitoring standards, e.g., standards such as >90 nm, >65 nm, or the like, are applied.